One thing that we know from decades of twin studies is that childhood family environment explains a vanishingly small percent of long-run adult outcomes.
Contextualizing this single study's result against the much larger, more established evidence from twin studies strongly suggests that one or more of the following is true.
- The results are spurious and won't replicate.
- The results are true, but the association is not causal, and is simply proxying correlation with an upstream factor.
- Lack of touch does lead to methylation in the short-term, but by adulthood there's strong reversion to the mean.
- The methylation has no significant impact on any actual metric that we care about like success, health, personality or wellbeing.
Contextualizing this single study's result against the much larger, more established evidence from twin studies strongly suggests that one or more of the following is true.
- The results are spurious and won't replicate.
- The results are true, but the association is not causal, and is simply proxying correlation with an upstream factor.
- Lack of touch does lead to methylation in the short-term, but by adulthood there's strong reversion to the mean.
- The methylation has no significant impact on any actual metric that we care about like success, health, personality or wellbeing.